Objective: Concern exists about a
possible increased risk of cerebrovascular events
(CVEs) among elderly patients receiving risperidone
or olanzapine. We estimated the effect of atypical and conventional antipsychotics on the risk
of CVEs among elderly nursing home patients with dementia.

Method: We conducted a case-control
study on residents of nursing homes in 6 U.S. states
by using the Systematic Assessment of Geriatric drug use via Epidemiology database, which
includes data from the Minimum Data Set linked to Medicare inpatient claims. Participants were
diagnosed with Alzheimer's disease or other forms of dementia on the basis of clinical criteria
and medical history (including medical records and neuroradiologic documentation). Cases
included patients hospitalized for stroke or transient
ischemic attack between June 30, 1998, and
December 27, 1999. For each case, we identified up to
5 controls hospitalized for septicemia or urinary tract infection residing in the same facility
during the same time period. The sample consisted
of 1130 cases and 3658 controls.

Results: After controlling for potential
confounders, the odds ratio of being hospitalized
for CVEs was 0.87 (95% CI = 0.67 to 1.12) for risperidone users, 1.32 (95% CI = 0.83 to 2.11)
for olanzapine users, 1.57 (95% CI = 0.65 to 3.82) for users of other atypical agents, and 1.24
(95% CI = 0.95 to 1.63) for conventional
antipsychotic users compared to nonusers of antipsychotics.
A history of CVEs appeared to modify the effect of atypical antipsychotics other than risperidone
on the risk of new events.

Conclusion: Overall, no increased risk
of CVEs seems to be conferred by atypical or conventional antipsychotics. Preexisting
cerebrovascular risk factors might interact with some
atypical antipsychotics to increase the risk of
events. These results should be interpreted in light of
the limitations of the study and need to be confirmed.